1. Field of the Invention
This invention is directed to pest repelling devices, in general, and to an electronically controlled, ultrasonic signal generating device, in particular, for repelling pests such as insects, rodents and the like.
2. Prior Art
There are many known types of pests and vermin which annoy, pester and/or adversely affect mankind. Many types of devices, processes, chemicals and the like have been used in the past in order to exterminate and/or repel such pests.
One problem, generally found in extermination, of pests is the use of toxic chemicals or similar components. These materials are, frequently, toxic not only to the undesired pests or vermin but also to mankind, domestic animals, pets and the like. Consequently, these types of products must be used with extreme caution. Moreover, these products are precluded from use in some areas. For example, it is highly undesirable to use these kinds of products around food and the like. Also, use of these materials is undesirable in that the pest can ingest or absorb the material and carry it away. Thus, the pest can expire in an inaccessible location causing the problem associated therewith in terms of attracting other pests or vermin and/or creating an unpleasant odor.
Other mechanical or electrical devices can be used such as applying force to physically eradicate or exterminate the pest. In other cases, the pest can be "zapped" by electronic means. As a result, the devices and related methods have difficulty that the unwanted pest or vermin is still exterminated on the premises which are to be controlled.
A much more desirable approach is to use a "perimeter defense" or the like which keeps the pests and vermin off the protected premises altogether. This has the advantage that no unwanted carcasses are discovered. Perhaps, most importantly, the initial invasion of the premises by the undesired pest or vermin is avoided or inhibited.